Delaying mains to backline

[tomhole]

With my new Yamaha 01v96 in hand, I now have the ability to delay the mains to the backline but was wondering if that is really necessary. We play on typical bar stages that are 10-12 ft deep (sometimes they are 20 ft deep at the "nicer" places). The mains are out front (duh) maybe 2 ft in front of the farthest mic stand. So, typical distance from back of stage to front of mains is 14-16'. Gtr amps are usually side firing halfway back, bass amp and drums in the back. With the 01v96, I have the ability to taylor each input's delay in the mains. For instance:

1. Delay vox mics 2-4 ft to match them up with the vox monitors
2. Delay the gtr inputs 6 ft
3. Delay the drum inputs 10 ft
4. Delay the bass input 12 ft

That would make everything sound like it is originating from the center of the stage.

I think this might be a good idea in that I took the time to SMAART my system and time align the subs to the tops which required 9 ft of delay on the tops (I have horn loaded subs). This makes a noticable difference in the quality of the sound. So it seems to make sense that aligning the bass amp on stage (which contributes a lot to the overall level of bass in the venue) to the mains (or vice versa).

Thoughts?

Tom

[B. Adams]

Sounds like a pain in the ass to me. I mean, it's a good idea, but it'll probably take a litte time to delay every single channel each time you set up. I'd go the basic route and just delay the whole PA to the backline and call it good.

As for delaying the vocals to compensate for 2 feet, what would be the point anyway? That's like 2 milliseconds, and who would notice that? Not to mention the fact that the only people close enough to hear the actual sound of the singers voice are at least 10' or so from the mains, and would then be hearing even more delay than normal.

I doubt too many people are going to complain about 20 milliseconds, much less 2. I can't see how delaying everything will improve anything. It will just make things more complicated than they need to be. Delaying to the backline probably isn't incredibly necessary either, but that's a really easy thing to do, and in many cases it probably won't change much night to night. You could probably just set it at 10ms or so and call it good most of the time.

[B. Adams]

You know, picker13, even though your post said a lot of the same things as mine, you didn't have to go and delete it like that. Nothing wrong with what you were saying.

I'm probably the only one who saw that, huh?

[tomhole]

Originally posted by B. Adams
Sounds like a pain in the ass to me. I mean, it's a good idea, but it'll probably take a litte time to delay every single channel each time you set up. I'd go the basic route and just delay the whole PA to the backline and call it good.

That's my line of thinking right now as well. But you know how it is with a new toy: I've got delays on every input and output and want to use them all :D And digital makes it 100 times worse. Let's see, if I route the L/R out back into bus 1 and that into bus 2 and that into bus 3 and bus 3 out to the mains, I can get 31 PEQ's and I won't need a 31 band eq on the mains. Now which fader controls the mains level?

Cheers,

Tom

[Centauri]

If you have already got 9 feet of delay on the tops (and therefore the PA), then you already have the PA delayed 7 feet back into the stage. I would think that in itself is quite close enough without any further delays.

Cheers

[dboomer]

Don't forget that using the 01v96 adds about 2 ms of latency itself. You can check with Smaart to be sure. It may change as you use different modules too, I'm not sure so check and let us know.

[picker13]

Originally posted by B. Adams
You know, picker13, even though your post said a lot of the same things as mine, you didn't have to go and delete it like that. Nothing wrong with what you were saying.

I'm probably the only one who saw that, huh?

Probably. I just got to thinking about the physics and became unsure of what the poster was asking, and if I was answering his question. So rather than confuse or add fuel to any sidetracking, I deleted my response.

So, to restate: When people say the "delay the backline" are they saying they are delaying the sources on the backline, or are they saying they are delaying everything else but the backline? And if the backline sources are going through the board, isn't it kind of a mess to start messing around with delaying for stage position? And then you have the problem of delaying the mic'd/DI'd signals for backline sources to "match" the natural, unmic'd/DI'd sound from the backline. I feel like a scene from Monty Python..."my brain hurts":)

[agedhorse]

Ok... this whole delaying to the back line thing is really a falsehood since you can't have a delay that works for anything other than a single point in the room for any one microphone. As soon as you move even 1 foot sideways, the delay amount changes. Also, do you delay for the left speaker distance or the right speaker distance, and for which position in the audience as you traverse an arc across the room?

I did a discussion with some of the basic math that illustrates why it's impossible in a past thread, so perhaps a search ofthe archives would be in order.. You can compensate for some gross offset, but it's a complete compromise regardless of what you do. Same applies to large stages, though the gross offset application still applies.

[picker13]

Originally posted by agedhorse
Ok... this whole delaying to the back line thing is really a falsehood since you can't have a delay that works for anything other than a single point in the room for any one microphone. As soon as you move even 1 foot sideways, the delay amount changes. Also, do you delay for the left speaker distance or the right speaker distance, and for which position in the audience as you traverse an arc across the room?

I did a discussion with some of the basic math that illustrates why it's impossible in a past thread, so perhaps a search ofthe archives would be in order.. You can compensate for some gross offset, but it's a complete compromise regardless of what you do. Same applies to large stages, though the gross offset application still applies.

That's kind of what I thought -- the physics just didn't work out. I understand getting your tops and bottoms in line, but everything else seems to give you results that are "more apparent than real"

[padudeohio]

There was a thread over on the LAB that discussed delaying the FOH to the backline. Most of them felt that just delaying to the loudest instrument on stage was enough. (ie: snare or that full mesa stack). In my opinion, at most club shows, the stages aren't deep enough to even bother with it

[Steve_B]

This subject has indeed come up several times on the LAB. It might be worth doing a search their for FOH and delay. The following is something I replied to a while back and still had floating around on my computer hard drive.

If you have got the time and inclination it is worth experimenting with time delays to the backline. Having tried every combination possible – simple single delay, stereo delays on individual instruments etc- the best that I can say is that delays make the sound, sound different. You might initially think that it is better, but maybe six months down the line when you are at a gig and you haven’t got time to add a delay or decide to try it without it suddenly sounds better without the delay. Another few months and things once again get better when you add that delay

Don’t bother with sophisticated measuring devices because there is not much point. It will certainly allow you to accurately align the individual sounds at the measurement microphone, but what sophisticated device do you use to position the microphone? I’ll use your example where the stage is 15ft deep (using feet means that we can approximate 1msec per foot) and assume that the PA stacks are 40ft apart. For someone stood immediately in front of and at the centre of the stage the PA is already 5msec behind the instrument. Staying on the centre line but moving away from the stage will cause the sound delay from the PA to get less until at some point the sound will arrive from both the PA and instrument at the same time. In the above example it will be about 6ft (if my mental arithmetic is correct). Remember the above time delays are without any additional electronic delay being added to the PA. From the 6ft point the PA signal will arrive increasingly ahead of the instrument up to a maximum of 15msec. So even staying on axis gives possible theoretical time delays of -5msec to 15msec; the choice is yours. Then, as others have said moving off axis complicates things even further.

Some of the best results that I have had has been using stereo delays. That is the time delay to each side of the PA has been set differently depending on the relative position of the instrument on stage. This obviously requires a stereo delay for each instrument that you want to apply the effect to. Don’t bother with test instruments, just do each side of the PA separately and slowly increase the delay until the sound from the PA disappears. This goes beyond actual alignment and into the realm of psycho-acoustics (did someone mention Mr Haas) but if set up correctly you get the power of the PA sounding as though it originates totally from the instrument. Unfortunately this only works within a small area, and because it relies on a psycho-acoustic effect, has variable results dependent upon the listener (at least that is what I have found). One person can think that the effect is stunning while another might wonder what the fuss is about. On a positive note adding these delays doesn’t seem to make it sound worse for anyone.

Getting back to simple alignment, don’t expect it to make a rubbish band sound good. Look on it as an embellishment. Best results seem to be with simpler less heavily produced types of music. If you intend to experiment, as well as a simple delay and the individual instrument approach, you might want to try delaying the back line and leaving the vocals undelayed. Just experiment.

Having been there, done that and got the T-shirt, I tend not to use delays that much and possibly use a stereo delay as an effect if there is a guitar or piano solo.

Hope this helps,

Steve.

[agedhorse]

Steve's example is similair to the one I used in my discussion also. Cool in theory but isn't worth all the effort.

[Scodiddly]

I wonder if trying to get "close" could cause more problems than it solves. Take balcony fill delays, for instance. The rule of thumb (which I got from the Yamaha book) is to figure out how many milliseconds you need to match the distance from the mains, and then add 10ms. Why? Because of a couple things - getting the phase exactly right for all the balcony seats, and also the apparent source of the PA sound. You want people to perceive the sound as coming from the mains, not that little speaker up there on the ceiling. Adding ~10ms seems to result in a perception of sound coming from the mains, but fleshed out because the balcony fill is there.

I'd worry that if you had the mains lined up nicely with the backline for a center seat, there'd be a phase difference for the side seats. By just leaving the mains undelayed, you'd probably get the same sound-source perception as the balcony fill example - from the backline, which is exactly what you'd want.

[agedhorse]

Of course relative phase (from the different sources) is completely irrelavent at 99% of all points in the audience. Add to that the hall reflections and it's a phase incoherant soup in the audience and most everywhere.